/**signal */
#include<stdio.h>
#include<stdlib.h>
#include<signal.h>
#include<unistd.h>
static void sig_handler(int sig)
{
	printf("received signal:%d\n",sig);
}

int main(void)
{
	sig_t ret=NULL;
	//ret=signal(SIGINT,(sig_t)sig_handler);
	//ret=signal(SIGINT,SIG_DFL);
	//ret=signal(SIGINT,SIG_IGN);
	//ret=signal(SIGKILL,SIG_IGN);
	ret=signal(SIGSTOP,SIG_IGN);
	if(SIG_ERR==ret){
		perror("signal error");
		exit(-1);
	}
	for(;;){
		sleep(1);
	}
	exit(0);
}
